Systematic Study of Alkali Cations Intercalated Titanium Dioxide Effect on Sodium and Lithium Storage

Abstract

have attracted wide attention as an energy storage device and exhibit the great development prospects. [1-3] Therefore, as a replacement, SIBs can offer an effective way to alleviate the contradiction between the restriction of lithium resources and the requirement of large-scale application of LIBs. So, the development of suitable anode materials are of great significance to the further advancement of SIBs. [4,5] Among all kinds of SIB anode materials, Ti-based materials, such as titanium oxides (e.g., rutile, anatase, and amorphous TiO 2) and titanate, have attracted more and more attention because of their good electrochemical reversibility, low cost and environmental friendliness and so on. [6-8] The alkali cations, like Li + , Na + and K + , as the adjacent elements in the same main group, have similar physical and chemical properties and are usually used as cations to prepare titanate materials. [9-11] The ionic radius for lithium, sodium and potassium increases from 0.76, 1.02 to 1.38 Å. [12,13] And the metallicity is also influenced by the radius. In addition, the electrode potential for Na + /Na, K + /K, Li + /Li is −2.71, −2.93, −3.04 V versus standard hydrogen electrode, respectively. [14,15] These differences of Li + , Na + , and K + indicate that their electrochemical properties will also change significantly when they are used as cation ions of titanate anode materials. In another aspect, the crystal structure of titanate A x Ti y O z (A-TO, A = Li + , Na + , and K +) is composed of Ti-O polyhedra with alkali cations inserted. The differences in respect of crystal structure lead to different nanostructures for the A-TO (A = Li + , Na + , K +) compounds. Notably, the electrochemical properties of these materials are closely related to their structures. [16,17] Recently, reasonable design of nanostructures has become an effective strategy to improve the electrochemical performance. For instance, Na 2 Ti 3 O 7 nanoarrays were used as the anode material for SIBs, exhibiting a high reversible capacity of 227 mAh g −1 at a high rate of 35 C. [18] While Na 2 Ti 3 O 7 hollow spheres can only provide a low capacity of 60 mAh g −1 at 50 C. [19] In addition, Li 4 Ti 5 O 12 nanosheets can derive a reversible capacity up to 145 mAh g −1 at 1 C after 400 cycles. [20] However, the porous Li 4 Ti 5 O 12 monoliths can only exhibit a lower discharge capacity of 104 mAh g −1 at 1 C. [21] Therefore, the design of Ti-based nanostructures with stable structure and appropriate interlayer spacing is of great significance to improve the kinetic of sodium and lithium storage. As discussed above, these differences The fast development of electrochemical energy storage devices necessitates rational design of the high-performance electrode materials and systematic and deep understanding of the intrinsic energy storage processes. Herein, the preintercalation general strategy of alkali ions (A = Li + , Na + , K +) into titanium dioxide (A-TO, LTO, NTO, KTO) is proposed to improve the structural stability of anode materials for so...

Rationally Designed Three‐Layered TiO2@amorphous MoS3@Carbon Hierarchical Microspheres for Efficient Potassium Storage

“…Therefore, the suitable anode materials are the key problem to be solved for the development of PIBs. [8][9][10][11] To date, a variety of anode materials for PIBs have drawn special attention, including alloy types, [12,13] carbon-based nanomaterials, [14,15] and chalcogenide compounds. [16] Notably, conversion mechanism materials like transition metal dichalcogenides (TMDs) have attracted much attention due to their unique two-dimensional (2D) layered structure and higher theoretical capacity.…”

“…Therefore, the suitable anode materials are the key problem to be solved for the development of PIBs. [ 8–11 ]…”

Boosting Charge Transfer Via Heterostructure Engineering of Ti2CTx/Na2Ti3O7 Nanobelts Array for Superior Sodium Storage Performance

“…Compared with the pure NTO electrode (Figure S10, Supporting Information), the charge curve of the Ti 2 C/NTO electrode has several distinct plateaus around 1.5-2.2 V, corresponding to the Ti 2 CT x (Figure S11, Supporting Information), which can further prove the existence of Ti 2 CT x of Ti 2 C/NTO electrode. In addition, the Ti 2 C/NTO electrode delivered the initial discharge and charge capacity of 409.4 and 230.4 mAh g -1 , corresponding to the initial coulombic efficiency (ICE) of 56.3%, which is obviously higher than that of the oxygen-deficient and bismuth-substituted HBNTO (17%), [49] alkali ions into NTO (24.4%), [50] hydrogenated Na 2 Ti 3 O 7 cubes with dual-shell structures (45.3%), [51] and sulfur-doped doubleshell Na 2 Ti 3 O 7 microspheres (54.7%). [52] That is the main structural advantage of the heterostructure in the Ti 2 C/NTO electrode, which can significantly decrease the number of NTO layers and effectively suppress many unwanted side reactions as well as irreversible trapping of Na + between reactive surface sites of NTO and electrolyte.…”

Recent Progress in Rechargeable Sodium Metal Batteries: A Review

“…Compared to the commonly used Cu foils, 3D carbon-based substrates with larger specific area show great potential to suppress Na dendrites and alleviate the volumetric expansion. [21][22][23][24][25] However, carbon-based materials usually exhibit sodiophobic properties and retard Na deposition. Surface modification is proposed to be effective to render the carbonbased materials with low Na diffusion and nucleation barriers.…”